Toolbars are used for connecting soil working tools to a tractor. The soil working tools mounted on tool bars are employed for planting and tilling crops such as corn and soybeans that are planted in spaced apart rows. Individual soil working gangs or units and planter units are clamped to the tool bar. The spacing between the gangs or units can be changed by loosening the mounting clamps, sliding the gangs or units along the toolbar to the desired position and then retightening the mounting clamps.
Planter units mounted on toolbars are attached to the tool bar by parallel links that allow the planter unit to float up and down relative to the toolbar. The planter units float up and down to insure that the openers open a slit to the proper depth and that seeds deposited in the slit are covered with the desired amount of soil. Seed placement and seed depth are very important factors affecting seed germination and crop yield.
Crops such as corn are commonly planed with planter units on large toolbars which plant 16 to 24 or even more crop rows on each pass through the field. A toolbar that plants 24 rows with 30 inch spacing between the rows plants a 60' strip on each pass. The amount of up and down float provided for planter units relative to the toolbar they are mounted upon is limited. To maintain uniform seed placement depth with large planters, it has been necessary to employ tool bars with hinged joints and floating wings when planting all but the flattest fields. With the hinge axis of large toolbars having planter units, located thirty to forty eight inches or more above the surface of a field, a slight change in the angle between two sections of the toolbar will make a substantial change in the space between the rows planted by planter units adjacent to the hinged joint. To cultivate between plant rows planted with a planter having a toolbar with floating wings, the row crop cultivator used to do the cultivating must have a toolbar with floating wings and wings with pivots in the same locations as the planter toolbar to accommodate the changes in row spacing. Row crop cultivator gangs would likely kill growing plants planted with planter units on a toolbar with floating wings if the row crop cultivator gangs are not mounted on a tool bar with floating wings. On the other hand crops planted in rows by planter units mounted on a rigid toolbar should be cultivated with cultivator gangs mounted on a rigid toolbar.
Toolbars with folding and floating wings have been provided with hardware for fastening the wings rigidly to a center section. The hardware generally includes threaded fasteners that clamp the wing to the center section and prevent pivotal movement about the axis of the pivotal connection between the wing and the center section. The operator must stop the tractor and use hand tools to change between a rigid wing and center section and a floating wing and center section.
Cultivator gangs and shanks that are cultivating soil which is compact and hard because it has not been cultivated for several months or has been compacted by machinery may require additional weight from the toolbar to hold the earth engaging tools at the desired working depth. Soil engaging tools on a floating wing may pivot the wing up and reduce soil penetration. While cultivating in such conditions, it is necessary to rigidly secure toolbar wings to the center section.
There are numerous obstructions in and around farm fields which may interfere with toolbars and the tools mounted on the toolbars. These obstructions include things like rocks, water drainage ditches, utility poles, roads, buildings, trees and irrigation structures. It can be very helpful to be able to fold a wing up to clear an obstruction. If you have an irrigation ditch or a road at each end of a field the tractor operator may need to fold the toolbar wings at each end of the field to turn around and make a pass across the field in the opposite direction. With some gangs or units, the overall width of a machine can be decreased substantially by folding the wings 180.degree. or close to 180.degree.. When the toolbar wings are folded 180.degree., the earthworking tools clamped to the wings extend upwardly rather than out to the side.